Auth.js vs Auth0

Side-by-side — pricing, strengths, tradeoffs, and fit.

Auth.js

Open-source authentication for the web (formerly NextAuth.js), free and framework-native.

Auth0

Enterprise-grade authentication and authorization platform with extensive identity-provider support.

Auth.js

Auth0

At a glance

Open SourceFree Tier

● Established·From $0

Free TierEnterprise

● Established·From $35/mo

Overview

One-liner

Open-source authentication for the web (formerly NextAuth.js), free and framework-native.

One-liner

Enterprise-grade authentication and authorization platform with extensive identity-provider support.

Maturity

Established

Maturity

Established

Open source

✓ Yes

Open source

✕ No

Pricing

Free tier

✓ Available

Fully free and open source

Free tier

✓ Available

25,000 monthly active users on the free plan

Starts at

$35/mo

Model

Flat rate

Model

Per MAU

Enterprise

✕ None

Enterprise

✓ Available

Best for

✓ Best for

Next.js apps wanting free, self-hosted authNative integration, no per-user cost

Developers comfortable owning auth plumbingFull control over sessions and providers

✓ Best for

Enterprise B2B apps needing SSO/SAMLMature enterprise connections and compliance

Teams needing fine-grained authorizationRBAC and Actions cover complex authz

Not ideal for

✕ Not for

—

✕ Not for

—

Strengths

↑ Strengths

Free and open source

First-class Next.js integration

Many OAuth providers built in

↑ Strengths

Deep enterprise identity features

Huge ecosystem of connections/rules

Battle-tested at scale

Weaknesses

↓ Weaknesses

Token rotation is broken, causing new tokens from external IDPs to be lost and old tokens to be reused indefinitely.

The v5 release is in beta with unclear stability and security implications for production use.

Session state is not updated on the client side after sign-out, requiring manual page reloads.

JWT modification for refreshing access tokens is not possible after initial login.

↓ Weaknesses

Essential enterprise features like Enterprise Connections and SCIM are not available on the Essentials or Professional plans.

The free tier requires credit card verification to enable custom domains.

Full Auth.js profile →Full Auth0 profile →